Recap Sony SL-HF600 for bad luma?
 

Hi all,

Today my Betamax Sony SL-HF600 deck starting having an on-off extreme luma drop during playback of a specific tape. Sometimes this would be in the form of a dark flicker, sometimes the image would just be dim for a few seconds, and sometimes the picture would be very dark (still visible in waveform monitor, but VERY low). It will go back to normal for a bit, then darken.

This appears in my preview monitor as well as my capture view. I'm led to believe the culprit is a dying cap somewhere in the deck (it's otherwise in decent shape), but not sure where to look. I do have a service manual to reference but have never had this exact issue before.

The problem so far is inconsistent and will sometimes go minutes before having another drop. Other tapes seem to play normally. I am also considering I am just working with poor dubs (tapes dubbed in the 80s) but again have not seen this before. Restarting the deck seems to momentarily stop this problem?

Any feedback would be helpful!

peace

: )

Obviously test it only with a known good tape. In an older deck caps become increasingly suspect but to which ones is more tricky. Measurement with an ESR meter is the usual procedure. But I'd first check easy things like external cables and connectors.